How to update firmware of ASUS RT-N56U

ASUS RT-N56U is a popular consumer wireless modem. It has been out for a few years already. So, if you bought it early on, it might be a good idea to update its firmware. Updating the firmware of this wireless modem is very easy:

Download the latest firmware: Go to the Driver and Tools page of the modem. In the dropdown choose Others and then Firmware. A list of firmware releases for this modem are listed. Download the latest stable version. Unzip the downloaded file and you will get a .trx file.

Open the web interface of your modem in your browser. You can see the current Firmware Version listed at the top. If this version is same as the latest available firmware, then you do not need an update.

In the web interface, go to Administration Firmware Upgrade. The modem checks if an updated firmware is available to download it. This download failed for my modem. I clicked through again to this same section of the interface. This time I manually chose my downloaded .trx file and it was uploaded to the modem.

As instructed by the modem, I restarted it after the upload by switching it off and back on. If you cannot connect back to the modem after the restart, you might want to factory reset it by pressing that button at the back for a few seconds. I had no problems connecting back and after opening the modem web interface, I saw that the firmware version was the updated one now.